The current altitude record for a small helicopter is:

FAI Class E1b - Altitude Without Payload - takeoff weight 500-1000 Kg
International: 40,820 ft; 12,442 m.
Jean Boulet (France)
Alouette SA 315-001 Lama
Artouste IIIB 735 KW engine
Istres, France June 21, 1972

John Hairell )

Well then, poor "Pedro", a stock H-43 didn't do too badly in 1959 at
somewhere near 10,000 m., wooden blades a'flappin'!

Old Chief Lynn